Junior Antonio Sanchez Rivero of Columbia works out at the weightlifting venue in preparations for the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Hassan Ammar)

Players warm up during a Beach Volleyball practice session at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Petr David Josek)

Austria's Amelie Solja serves a ball during a training session at the ExCel Centre, where the table tennis events will be held at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Sergei Grits)

Great Britain's Zara Phillips runs with her horse High Kingdom during horse inspection for the equestrian eventing competition at Greenwich Park, the site for the equestrian and modern pentathlon events at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Markus Schreiber)

Canada's Meaghan Benfeito, left, and Roseline Filion perform a dive during a training session at the Aquatics Centre at the Olympic Park ahead of the 2012 Summer Olympics, Friday, July 27, 2012. (AP Photo/The Canadian Press, Frank Gunn)

A member of Canada's women's eight crew reaches from the boat during training in Eton Dorney, near Windsor, England, at the 2012 Summer Olympics, Friday, July 27, 2012. The rowing competition starts on Saturday. (AP Photo/Natacha Pisarenko)

Jennet Saryyeva of Turkmenistan puts on her goggles during a practice session at the Aquatics Centre in the Olympic Park ahead of the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Daniel Ochoa De Olza)

South Korea's Im Dong-Hyun, right, inspects his arrows on the target next to Taiwan's Kuo Cheng-Wei, in Blue, during an individual ranking round at the 2012 Summer Olympics, Friday, July 27, 2012, in London. Dong-Hyun set world record in the round with a 699 score.(AP Photo/Marcio Jose Sanchez)

Ingo Kindervater of Germany practices during a training session of the badminton competition at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Saurabh Das)

Drivers stand alongside stationary cars in a traffic jam on Park Lane in central London, as taxi drivers protested over a ban on using Olympic traffic lanes on Friday July 27, 2012. The 2012 Summer Olympics begin with opening ceremonies on Friday. (AP Photo/Dominic Lipinski, PA) UNITED KINGDOM OUT; NO SALES; NO ARCHIVE

Members of the New Zealand cycling team train ahead of the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Matt Rourke)

Argentina's Agustin Mazzilli and South Korea's Nam Hyun-woo tangle their sticks during a practice match for the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Eranga Jayawardena)

U.S. first lady Michelle Obama plays with schoolchildren during a 'Let's Move!' event for about 1,000 American military children and American and British students at the U.S. ambassador's residence in London, ahead of the 2012 Summer Olympics, Friday, July 27, 2012. (AP Photo/Lefteris Pitarakis)

Canadian swimmer Brent Hayden does kicking drill during a training session for the London 2012 Olympics in London, Friday July 27, 2012. (AP Photo/The Canadian Press, Frank Gunn)

A man has the Olympic rings shaved into his hair in London, Friday, July 27, 2012. The city is hosting the 2012 Summer Olympics, beginning with opening ceremonies on Friday. (AP Photo/Emilio Morenatti)

Archers stack up during an individual ranking round at the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Marcio Jose Sanchez)

Daniele Molmenti, of Italy, gestures during training for the men's K1 kayak slalom at the Lee Valley White Water Center ahead of the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Victor R. Caivano)

Casey Eichfeld of the United States trains for the men's C1 canoe slalom at the Lee Valley White Water Center ahead of the 2012 Summer Olympics, Friday, July 27, 2012, in London. (AP Photo/Victor R. Caivano)